PatchTheCVECVE-2026-62857: Fedify is a TypeScript library for building federated server apps powered by ActivityPub
CVE-2026-62857 is a high-severity flaw (CVSS 8.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. From version 1.2.0 through the affected 1.9, 1.10, 2.0, 2.1, 2.2, and 2.3 maintenance lines, getNodeInfo() follows an attacker-controlled links[].href value from /.well-known/nodeinfo without scheme, redirect, or private-address validation, allowing requests to loopback, link-local, cloud metadata, and private-network services and returning their response bo
Why this priority
- High severity
- CISA SSVC: public proof of concept
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.8 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 65%) |
| CISA exploited list | No |
| Weakness | CWE-918 |
| Published | 2026-08-06 |
| Last modified | 2026-10-24 |
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-62857?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-62857 being exploited?
CVE-2026-62857 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-62857 affect?
CVE-2026-62857 affects affected software. Severity is high (CVSS 8.8). Fedify is a TypeScript library for building federated server apps powered by ActivityPub. From version 1.2.0 through the affected 1.9, 1.10, 2.0, 2.1, 2.2, and 2.3 maintenance lines, getNodeInfo() follows an attacker-controlled links[].href
How urgent is CVE-2026-62857?
Priority 48/100. High severity; CISA SSVC: public proof of concept; Remotely exploitable, no login, no user action